Concrete form structure for floors



June 25, 1968 w. K. H. GREGORI 3,389,521

CONCRETE FORM STRUCTURE FOR FLOORS Filed Aug. 3, 1966 2 Sheets-Sheet 1FIG. 2

INVENTOR. WERNER K. H. GREGORI ATTORNEYS June 25, 1968 w. K. H. GREGORI3,389,521

CONCRETE FORM STRUCTURE FOR FLOORS Filed Aug. 5. 1966 2 Sheets-Sheet 2INVENTOR. WERNER K. H. GREGORI F|G.4 5 a My.

ATTORNEYS United States Patent 3,389,521 CONCRETE FORM STRUCTURE FORFLOORS Werner K. H. Gregori, 121 Allen St.,

Oakville, Ontario, Canada Filed Aug. 3, 1966, Ser. No. 569,865 Claimspriority, application Canada, June 2, 1966,

961,887 Claims. (Cl. 52-309) This invention relates to buildingconstruction and is particularly concerned with a preassembled concreteform structure for use in the construction of concrete floors andintended to be left within the poured floor and to provide a finishedceiling surface for the under side of the poured floor.

The commonly used method of constructing a concrete building floor ofthe type which also provides a ceiling for a space beneath the floor isto erect temporary scaffolding supporting plywood or the like sheets onto which the concrete is poured. Following setting of the concrete, thescaffolding and plywood are removed and the under side of the floorfinished in a traditional manner to provide a finished ceiling surfacefor the space beneath the floor. This known manner of constructing aconcrete floor can be expensive, both due to the time involved inremoving the scaffolding and plywood sheets following setting of theconcrete and due to the time involved in finishing the underside of thepoured floor.

It is, therefore, a chief object of this invention to provide a concretefloor structure which can be left in place following setting of theconcrete and which provides a finished under surface to the floor,thereby avoiding the need to finish this under surface in thetraditional manner known heretofore.

It is a further object of the invention to provide a form structure of.the above type which includes insulation material within the finishedfloor.

It is a further object of the invention to provide channelways orrecesses within the poured floor whereby to achieve a saving in concreteand a reduction in the weight of the fioor without reducing thestructural strength of the floor.

It is a further object of the invention to provide a form structure ofthe type described above which is adapted to receive the usual steelreinforcing rods which are often specified for use within concretefloors.

A further specific and related object of the invention is to provide aform structure which is adapted to receive reinforcing rods running intwo directions.

The above and further objects of the invention will be more thoroughlyunderstood from the following description of preferred embodimentsthereof as read in conjunction with the accompanying drawings.

In the drawings which illustrate these embodiments of the invention,

FIG. 1 is a perspective view of a form structure in accordance with afirst embodiment of the invention and showing the manner in which theform structure is adapted to receive reinforcing rod and wire mesh forstrengthening the poured concrete;

FIG. 2 is an enlarged vertical cross-sectional view through one end of aform structure of the type illustrated in FIG. 1 and showing the mannerin which this form structure is associated with a building wall;

FIG. 3 is a perspective view of a form structure in accordance with asecond preferred embodiment of the invention with portions of thestructure being broken away for better illustration; and FIG. 4 is aperspective view showing the manner in which the term structure of theembodiment of FIG. 3 is used in forming a concrete floor.

3,389,521 Patented June 25, 1968 Referring to FIG. 1, it should beunderstood that the form structure in accord with this particularembodiment is adapted to receive and support the weight of the pouredconcrete without assist from temporary scaffolding or other bracingbelow. The structure essentially consists of a lower panel element 10adapted to provide a finished ceiling surface for the under side of thepoured floor and a plurality of semi-tubular elements 12. The panelelement 10 may consist of a number of different materials depending uponthe desired nature of the ceiling finish desired. In the normal course,panel element 10 will be formed of a gypsum board but it will beappreciated that should some other type of ceiling finish be desired,the gypsum board will be replaced in the structure by such sheetmaterial as is desired. The semi-tubular elements 12 are preferablyformed of fibre-board and may be made simply by slicing fibreboard tubeslongitudinally. Fibreboard is a preferred material as it gives highstrength with light weight but here too, it should be understood thatalternative materials for the semi-tubular elements are possible withinthe scope of the invention.

The semi-tubular elements 12 are fixed to the panel element 10 byapplying a suitable adhesive to their longitudinal edges with the choiceof adhesive depending upon the particular materials used in these twoelements. In the case of fibreboard elements 12 and gypsum board, asuitable adhesive is the syntheic rubber based glue sold under the tradename Bondmaster K 727 by the Adhesive Products Division of thePittsburgh Plate Glass Company.

In the embodiment of the invention illustrated in FIG. 1, there is showntwo semi-tubular elements 12. However, it should be understood thatvariations on the number and size of the elements 12 are possible. Inall cases, however, the semi-tubular elements are positioned insideby-side parallel relationship. Fixed to the top surface of the panelelement 10 between the semi-tubular elements 12 and at the side edges ofthe structure are a number of reinforcing strips 14 which are alsopreferably formed of fibreboard. These strips 14 are also adhesivelyattached to the top surface of the lower panel element 10' and they arealso glued along their side edges to the outer surface of thesemi-tubular elements 12. In manufacturing the structure of FIG. 1, itis the strips 14 which are first fixed to the panel element 10' with thesemi-tubular elements 12 being installed following setting of the glueholding the strips 14 to the panel element '10. The reinforcing strips14 serve as locaters for the semi-tubular elements but, of greaterimportance, they prevent outward spreading of the lower ends of thesemi-tubular elements under the infiu ence of the weight of eventuallypoured concrete.

To complete the form structure of FIG. 1, strips of insulation material16 are adhesively attached to the top surface of the fibreboard strips14 and directly to the top surface of the gypsum board panel element '10within the semi-tubular elements 12. These insulation strips preferablycomprise an expanded polystyrene foam, such as the material sold underthe trade name Styrospan by Dow Chemical of Canada Limited but suitablealternative material-s such as expanded urethane foam and foamed glassmay be used. The same adhesive mentioned above is suitable for attachingthese altenrative foam materials to the gypsum board. The foam selectedshould, of course, have good thermal insulation properties and beself-extinguishing.

To provide means whereby the side edges of the structure may beinterlocked with the side edges of similar structures in laying anextended floor area, the side edges are provided with an overlap on oneside and an underlap on the other simply by extending the fibreboardstrip adjacent one side of the structure laterally beyond the associatedside edge of the gypsum board in the case of the overlap or extendingthe gypsum board beyond the side edge of the associated fibreboard stripin the case of the underlap.

The form structure is shipped to the building site in the manufacturedcondition as above described. In using the form structure incircumstances requiring reinforcing rod within the concrete floor, anumber of reinforcing rods 20 are laid between the semi-tubular elementsand on either side thereof. In fact, these rods are spaced above thesurface of the foam by resting them on small brackets known as chairs 22in accordance with known techniques. More or less reinforcing rods maybe used, depending upon the strength required in the completed floor. Asa further known expedient, a wire mesh grid 24 may be laid on top of thestructure whereby to prevent crazing of the top surface of the pouredconcrete. This use of such a wire mesh is also a. known expedient.

The concrete or other cementitious material is poured to a depthextending approximately two inches above the semi-tubular elements 12.The dashed line 24 indicates the approximate depth of the pouredconcrete. As previously mentioned, the form structure of the embodimentof the invention shown in FIGS. 1 and 2 is capable of supporting theweight of the poured concrete without support bracing. A typical mannerin which the form structure will be associated with a previously pouredconcrete or the like wall is shown in FIG. 2. The form structure issupported on a suitable ledge formed in the wall and one of the concretereinforcing rods extending upwardly from the poured concrete wall may bebent over and fixed to one of the reinforcing rods laid on the formstructure. The concrete is then poured on the form structure as to formthe floor. As a preferred expedient in using the structure of theinvention, the joints between overlapped structures are taped prior topouring of the concrete as to prevent seepage of cement through theoverlapped joints which would interfere with the appearance of the undersurface which constitutes the ceiling of the space beneath the pouredfloor.

The embodiment of the invention illustrated in FIGS. 3 and 4 consists ofa lower panel element of gypsum board or the like 36 having a shortlength 38 of a semitubular material of fibreboard fixed to the topsurface of the gypsum board. Foam insulation material 40 is fixed to thegypsum board all around the semi-tubular element 38 and is also used toblock off the two ends of the semi-tubular element. As in the case ofthe first described embodiment, the form structures of FIGS. 2 and 3 areprovided with overlaps and underlaps on their side edges whereby theymight be smoothly associated with like form structures in a large floorarea.

The form structure of FIGS. 3 and 4 is used where it is required to havereinforcing rods extending in both directions. While the form structureof FIGS. 1 and 2 is capable of supporting by itself the weight of thepoured concrete due to the structural strength of the elongatedsemi-tubular elements 12, the use of a plurality of short semi-tubularelements 38 in accordance with the embodiment of FIGS. 3 and 4 dictatesthe use of the usual temporary support scaffolding consisting of, forexample, sheets of plywood 42 supported by bracing members 44.

Iowever, the same advantage wherein the form structure of FIG. 1provided an already finished ceiling surface for the under side of thefloor is obtained by the form structure of FIGS. 3 and 4.

In using the form structures of the second embodiment, the procedure isquite similar to the procedure in using the form structure of FIGS. 1and 2 with the exception that reinforcing rods are laid in bothdirections. The same type of interconnection between the reinforcingrods in the floor and the reinforcing rods in the associated walls maybe used when employing the form structures of FIGS. 3 and 4.

It is also to be noted that in accordance with the embodiment of FIGS. 3and 4, no fibreboard elements comparable to strips 14 of the embodimentof FIGS. 1 and 2 are used. In the FIG. 1 embodiment, these fibreboardelements themselves provide structural strength in the structure wherebyto better support the weight of the poured concrete but in addition theyserve to strengthen the semi-tubular elements 12 by preventing them fromspreading apart and it is the semi-tubular elements which provide themain structural strength in the form structure of FIGS. 1 and 2. Sincethe same structural strength is not required in the embodiments of FIGS.3 and 4 because it is necessary to support the structures fromunderneath in any case, the use of the fibreboard board-like elements iseliminated.

In both embodiments of the invention, there is the advantage that theform structures are left in the poured floor and provide a finishedunder surface for the floor as to provide a finished ceiling surface forthe space beneath the floor. Further, the floor is provided with foaminsulation. Still further, the volume of cement or concrete required inthe floor is considerably reduced without interfering with thestructural strength of the floor. In addition, of course, the embodimentof FIGS. 1 and 2 has the further advantage that its use eliminates theneed for any temporary support structure. Further in the FIGS. 1 and 2embodiment, the semi-tubular members provide excellent channels throughthe floor for conduits and the like.

I claim:

1. A preassernbled concrete form structure for use in the constructionof a concrete floor and intended to be left within the poured floor andto provide a finished ceiling surface for the under side of the pouredfloor, said structure comprising a panel element of a material suitableas a finished ceiling surface and carrying on its top face at least onesemLtii-bular member of a. rigid material, said semi-tubular memberhaving its convex surface facing upwardly and its lower edges adhesivelyfixed to said top face of said panel element, and a layer of insulatingmaterial overlying and adhesively fixed to said panel element aroundsaid semi-tubular element, said insulating material consisting of arigid self-extinguishing, thermal insulating plastic foam.

2. A preassembled concrete form structure for use in the construction ofa concrete floor and intended to be left within the poured floor and toprovide a finished ceiling surface for the under side of the pouredfloor, said structure comprising a panel element of a material suitableas a finished ceiling surface, a plurality of semitubular members of arigid material having their convex surfaces facing upwardly and theirlower edges adhesively fixed to the top face of said panel element, saidsemitubular members being arranged parallel to one another, spaced fromone another and spaced from the side edges of said structure, strips ofrigid material adhesively fixed to the top face of said panel elementbetween said semitubular members and between said semi-tubular membersand the side edges of said structure, and strips of thermal insulating,fire resistant material overlying and adhesively fixed to said strips ofrigid material and overlying and adhesively fixed to the top face ofsaid panel element beneath said semi-tubular members.

3. A preassembled concrete form structure as claimed in claim 2 whereinsaid panel members and said strips of rigid material are formed offibreboard.

4. A preassem'bled concrete form structure as claimed in claim 3 inwhich said panel element is formed of gypsum board and in which saidstrips of thermal insulating, fire resistant material are formed ofplastic foam.

5. A preassembled concrete form structure as claimed in claim 4 in whichsaid plastic form is expanded polystyrene foam.

6. A preassem'bled concrete form structure as claimed in claim 5 whereinthe side edges of said structure are provided with underlaps andoverlaps, said underlaps being provided by extending the side edge ofsaid panel element beyond the associated strips of fibreboard andplastic foam, said overlap being provided by expanding the strips offibreboard and plastic foam beyond the associated side edge of saidpanel element. 1

7. A preassernbled concrete form structure for use in the constructionof a concrete floor and intended to be left within the poured floor andto provide a finished ceiling surface for the underside of the pouredfloor, said structure comprising a panel element of a material suitableas a finished ceiling surface and carrying on its top face a shortlength of semi-tubular rigid material having its convex surface facingupwardly and having its lower edges adhesively fixed to the top face ofsaid panel element, and a layer of thermal insulating, fire resistantmaterial surrounding said semi-tubular element and adhesively fixed tothe top face of said panel element and semi-circular pieces of thermalinsulating, fire resistant material closing the opened end of saidsemi-tubular element with said semi-circular pieces of thermalinsulating material being adhesively fixed to the under face of saidsemi-tubular element and to the top face of said panel element.

8. A preassembled concrete form structure as claimed in claim 7 whereinsaid semi-tubular element is formed of fibreboard, said panel elementbeing formed of gypsum board, said insulating material being formed of arigid plastic foam.

9. A preassembled concrete form structure as claimed in claim 8 in whichsaid rigid plastic foam is expanded polystyrene foam.

10. A preassembled concrete form structure as claimed in claim 9 inwhich said structure is substantially rectangular in shape and in whichtwo of the side edges of said structure are provided with underlaps andin which the other two side edges are provided with overlaps, saidunderlap edges having the panel element extended beyond the associatedportions of said insulating layer, said overlaps having the insulatinglayer extended beyond the associated portions of said panel element.

References Cited UNITED STATES PATENTS 1,090,718 3/1914 Hyer 52-577 X1,946,180 2/1934 Smith 52-438 FOREIGN PATENTS 393,137 1933 GreatBritain.

JOHN E. MURTAGH, Primary Examiner.

1. A PREASSEMBLED CONCRETE FORM STRUCTURE FOR USE IN THE CONSTRUCTION OFA CONCRETE FLOOR AND INTENDED TO BE LEFT WITHIN THE POURED FLOOR AND TOPROVIDE A FINISHED CEILING SURFACE FOR THE UNDER SIDE OF THE POUREDFLOOR, SAID STRUCTURE COMPRISING A PANEL ELEMENT OF A MATERIAL SUITABLEAS A FINISHED CEILING SURFACE AND CARRYING ON ITS TOP FACE AT LEAST ONESEMI-TUBULAR MEMBER OF A RIGID MATERIAL, SAID SEMI-TUBULAR MEMBER HAVINGITS CONVEX SURFACE FACING UPWARDLY AND ITS LOWER EDGES ADHESIVELY FIXEDTO SAID TOP FACE OF SAID PANEL ELEMENT, AND A LAYER OF INSULATINGMATERIAL OVERLYING AND ADHESIVELY FIXED TO SAID PANEL ELEMENT AROUNDSAID SEMI-TUBULAR ELEMENT, SAID